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SARS-CoV-2-pneumonia emerged in Wuhan, China in December 2019. Unfortunately, there is lack of evidence about the optimal management of novel coronavirus disease 2019 (COVID-19), even less in patients on maintenance hemodialysis (MHD) therapy than in the general population. In this retrospective observational single-center study we analyzed the clinical course and outcomes of all MHD patients hospitalized with COVID-19 from March 12th to April 10th, 2020 as confirmed by real time polymerase chain reaction. Baseline features, clinical course, laboratory data, and different therapies were compared between survivors and non-survivors to identify risk factors associated with mortality. Among the 36 patients, 11 (30.5%) died and 7 could be discharged within the observation period. Clinical and radiological evolution during the first week of admission were predictive of mortality. Among the 36 patients, 18 had worsening of their clinical status, as defined by severe hypoxia with oxygen therapy requirements greater than 4 Liters/minute and radiological worsening. Significantly 11 out of those 18 patients (61.1%) died. None of the classical cardiovascular risk factors in the general population were associated with higher mortality. However, a longer time on hemodialysis (hazard ratio 1.008(95% confidence interval 1.001-1.015) per year), increased LDH levels (1.006(1.001-1.011), and lower lymphocyte count (0.996 (0.992-1.000) one week after clinical onset were all significantly associated with higher mortality risk. Thus, the mortality among hospitalized hemodialysis patients diagnosed with COVID-19 is high. Lymphopenia and increased LDH levels were associated with poor prognosis., Graphical abstract

Background: Native autologous arteriovenous fistula (AVFn) is the preferred vascular access for hemodialysis due to its long term patency and low complication rate. A challenging limitation is the anatomical inability to perform AVFn and failure of maturation. Preoperative isometric exercise (PIE) can increase vascular calibers and improve the rate of distal AVF. However, it is unknown whether PIE might enhance the performance of AVFn in patients who are not initially candidates. Methods: A retrospective observational study was conducted over a population of 45 patients evaluated in vascular access clinic, 23 were not initially candidates for radiocephalic (NRC-AVF) and 22 were not candidates for autologous fistula at all (NA-AVF). They were assigned to perform PIE with handgrip device and revaluated. Results: After 4–8 weeks of PIE, a AVFn was performed in 16 patients from NA-AVF group and a radiocephalic AVFn was performed in 21 patients from NRC-AVF group. Both groups experienced a significant and similar increase in venous caliber 0.91 ± 0.43 mm in NA-AVF versus 0.76 ± 0.47 mm in NRC-AVF ( p = 0.336) and arterial caliber 0.18 ± 0.24 mm versus 0.18 ± 0.21 mm ( p = 0.928), respectively. Nevertheless, primary failure rate was significantly higher in NA-AVF ( n = 8, 50%) than in NRC-AVF group ( n = 3, 14.3%) ( p = 0.030). After 6 months, the fistula usability for dialysis was only 50% in NA-AVF, while 86.7% were dialyzed by fistula in NRC-AVF group ( p = 0.038). Conclusions: PIE allowed the allocation of an AVFn in patients not initially candidates, but entailed a high rate of maturation failure. Patients not candidates to radiocephalic AVF benefited from PIE and preserved a long term usability of AVF for dialysis.

Pentoxifylline could reduce proteinuria and slow renal disease progression. We previously conducted a single-blind, randomized, controlled trial that showed that pentoxifylline decreases inflammatory markers and stabilizes renal function. 91 participants (46 in the pentoxifylline group and 45 in the control group) followed up for 7 additional years. Post hoc analysis of a long-term follow-up after completion of the 12-months trial. Pentoxifylline treatment (400 mg/twice a day) or standard treatment. Renal event (defined as starting dialysis therapy and/or doubling serum creatinine and/or ≥ 50% decrease in estimated glomerular filtration rate) and cardiovascular mortality. During follow-up, a renal event was recorded in 24 patients from control group (13 initiated dialysis therapy and serum creatinine doubled in 11) and 11 patients from PTF group (7 initiated dialysis and serum creatinine doubled in 4) (log Rank: 5.822, p = 0.016). The possible protector effect of PTF was more significant in albuminuric patients and was independently of diabetes mellitus presence. Treatment with PTF reduced the renal events by 35% compared to the control group in a Cox model adjusted for diabetes mellitus, albuminuria and basal renal function (HR 0.65 (0.45–0.94), p = 0.022). Cardiovascular mortality was significantly reduced in PTF treatment (2 patients vs. 10 in control group) (log Rank 5.0977, p = 0.024). PTF treatment reduced cardiovascular mortality in 55% adjusted for diabetes mellitus and age (HR 0.45 (0.21–0.98), p = 0.044) (Table 3). Small sample size, single center, not double blind and post hoc follow-up analysis. Long-term treatment with pentoxifylline may slow the rate of progression of kidney disease and reduce cardiovascular risk.

There is no evidence about the potential role of body composition on cardiovascular mortality in dialysis patients. The aim of this study was to assess the relationship between body composition and changes in ventricular function. We conducted an observational study over a population of 78 patients on chronic hemodialysis. A transthoracic echocardiogram and a bioimpedance were performed at the beginning and at the end of the study. The mean follow-up time was 30.6 months. Patients who had a higher fat tissue index (FTI > 9.20 kg/m2 ) experienced a worsening in right and left ventricular function. They developed a greater fall in tricuspid annular plane systolic excursion (TAPSE) (-1 ± 4.3 mm) and left ventricular ejection fraction (LVEF)(-4.2 ± 6.8%), compared to those with lower FTI (p = 0.032 and p = 0.045, respectively). No associations were found between any other echocardiography or body composition parameters and overall mortality. Patients with right ventricular dysfunction (determined as TAPSE) experienced a tendency to higher mortality rate along the study (HR for mortality of 13.5 (95% CI, 1.1-166.7; p = 0.041)]. A higher fat tissue index could be associated with a deleterious effect over right and left ventricular function in dialysis patients.

Background and Aims Although metformin-associated lactic acidosis (MALA) is a very rare event, is frequently seen in patients on metformin with risk factors for developing acute kidney injury (AKI). The long-term prognosis in patients with metformin-associated lactic acidosis (MALA) and renal failure remains unknown. To describe the characteristics and prognosis of AKI in patients with MALA and investigate whether prescription of RRT and previous renal function are associated with long-term outcomes. Method A retrospective single-centre case series. One hundred and nine patients affected with MALA and AKI admitted between Marx 2007 and February 2019 were included. We analysed comorbidities, laboratory tests, clinical parameters and prescription pattern of RRT at admission. After discharging, renal outcomes (doubling serum creatinine or starting dialysis) and mortality were assessed in the long-term. Results We included 109 patients (59 males and 50 females), mean age of 74.2±8.6 years and mean Charlson comorbidity index of 8.0±2.4. 54 out of 109 patients had previous chronic kidney disease (eGFR < 60 ml/min/1.72 m2). Precipitating causes of AKI associated MALA included; acute dehydration (84.4%), exposure to iodinated contrast (7.3%) and non-specified causes (8.3%). During the admission, renal replacement therapy (RRT) was performed in 72 patients (continuous renal replacement therapy in 47 and dialysis in 25). RRT requirements was significantly associated with lactate, acidosis and serum creatinine levels, but not was associated with higher mortality rate during admission. The patients were followed a median time of 33 (10-65) months after discharging. 33 patients had a renal event and 55 patients died. The patients with CKD before admission had higher number of renal events (log Rank 6.346, p=0.012) and higher mortality (log Rank 12.943, p Conclusion The renal function prior to the episode of AKI associated to MALA and the RRT at admission are the main factors related to renal outcomes and mortality in the long-term.

Background and Aims Metformin is the antidiabetic of choice in patients with type 2 diabetes mellitus. Experimental studies and clinical observations have shown that metformin could have a beneficial effect on the progression of kidney disease through the activation of cAMP due to its anti-inflammatory, antifibrotic, and anti-oxidative action. The objective was to compare the progression of CKD in diabetic patients with or without metformin as antidiabetic in their treatment and the prevalence of cardiovascular events in both groups. Method Unicentric retrospective observational analysis. Inclusion criteria: outpatients seen in nephrology consultation during the year of 2012 with diabetes mellitus and stage 3 CKD. Renal, cardiovascular outcomes and mortality were analyzed between patients treated with / without metformin. Median follow-up of 76.5 months (41-84). Renal end-point: estimated glomerular filtration rate drop (MDRD-4) by 50% and / or start of dialysis program. Cardiovascular end-point: ischemic heart disease, stroke, arterial revascularization and / or amputation. Cardiovascular or any cause mortality. Results 148 patients (96M, 52W) with a mean age of 75±9 years and an eGFR of 40±9 ml / min / 1.73 m2 were included. In relation to hypoglycemic therapy: 45 received metformin, 61 insulin and 31 DPP4i. 80% received treatment with RAAS blockers. After the follow-up, the progression of the renal disease was greater in patients who did not receive metformin: eGFR fall of -7.0±16 vs -0.15±16 ml / min in those treated with metformin (p = 0.019). 25 patients in the group without metformin suffered a renal event vs. 5 in the metformin group (logRank: 4.186, p = 0.045). In the Cox analysis, metformin treatment decreases the progression of kidney disease in a model adjusted for baseline renal function and treatment with RAASB (HR 0.368, p = 0.043), losing its predictive power in a proteinuria-adjusted model. During the follow-up, 45 patients died (20 metformin, 25 non-metformin) and 45 patients suffered a cardiovascular event (15 metformin, 30 non-metformin), with no differences between the two groups. Conclusion Metformin treatment in patients with stage 3 CKD could slow the progression of CKD, this effect should be demonstrated in randomized studies with larger sample size.

Background and Aims Right ventricular dysfunction is common among hemodialysis (HD) patients and it has been recently described as a marker of cardiovascular morbidity and mortality. Nevertheless, mechanisms responsible for have not been clearly elucidated. Volume overload, retrograde left ventricular dysfunction, pulmonary hypertension, left-right shunt and mineral bone disease have been related. Similarly, body composition and chronic fluid overload are closely linked to survival in dialysis patients. However, there are no data about correlation between body composition and echocardiographic parameters in previous studies The aim of this study was to assess the relationship between body composition and changes in right and left ventricular function in patients on maintenance hemodyalisis. Method We conducted a retrospective and longitudinal observational cohort study over a population of 78 patients on maintenance hemodyalisis at a single hospital. They were on chronic hemodyalisis program of three weekly sessions of 240 minutes duration. A transthoracic echocardiogram (TTE) and a bioimpedance (BI) were performed in the same month, in the first inter-dialysis day of the week, being the patients asymptomatic and clinically stable, at the beginning and at the end of the study. The follow-up time since the completion of first and second ETT and BI was 19.5 months, with an average total follow-up of 29.7 months. Cardiovascular and general mortality events were recorded during that period. Echocardiography data about cardiac cavities measurement, ventricular and valvular function was collected. Left ventricular ejection fraction was evaluated by Simpson’s method (LVEF, %) and right ventricular function by tricuspid annular plane systolic excursion (TAPSE, mm).We gathered information about fluid status and corporal composition. Statistical analysis was performed using SPSS Statistics, version 21 (SPSS, Inc., Chicago, IL, USA). Results Patients with RV dysfunction (35.7%), determined as TAPSE < 20, experienced a higher mortality rate (20%) compared to those who maintained TAPSE ≥ 20 (63.2%), who had a mortality rate of 2.3%. These results were statistically significant in the Kaplan-Meier survival analysis (Log Rank 6.65; p = 0.010). There were not statistically significant differences regarding age, diabetes, years on dialysis and status of volume overload between patients with and without right ventricular dysfunction. No significant differences were found between any other of the echocardiography parameters and overall mortality. Equally, neither bioimpedance measure at the beginning of the study was associated with mortality. Patients who had an FTI above the average (9.20 kg / m2) suffered a greater fall in TAPSE (-1 ± 4.3 mm) (p = 0.032) and LVEF (-4.2 ± 6.8) (p = 0.045), regarding those with lower FTI: TAPSE +2.3 ± 4.3 and LVEF +3.7± 10.4. These results seems to be related to a disproportionate LTI/LTI index rather than a greater total mass of fat due to patients with FTI > 9.2 kg/m2 had a mean LTI/FTI index of 1.1, meanwhile those with FTI < 9.2 kg/m2 a mean LTI/FTI of 5.9. No statistically significant relationship was found with absolute or relative volume overload, nor with changes in them over time. Conclusion The results presented suggest that high fat tissue index, and an underlying lower LTI/FTI index, could be associated with a higher risk of right and left ventricular dysfunction, which has been associated with higher mortality in hemodialysis patients.

Background and Aims Retention of ß2microglobulin (ß2M), an uremic toxin in the middle molecular range, has been associated with cardiovascular morbidity and mortality in dialysis patients. Although ß2M levels are usually measured in hemodialysis patients, this practice is not common among peritoneal dialysis (PD) patients. The aim of this study is to evaluate the evolution of serum ß2M levels in incident PD patients. Method Prospective, observational study including incident PD patients in our hospital from January 2015 to October 2019. Patients with cardiorrenal syndrome or patients coming from hemodialysis were excluded. Serum ß2M levels were collected before starting PD and during follow up. Weekly KtV, residual renal function and cardiovascular events were also collected during follow up. Results We included 30 patients with a mean age of 57 +/- 17 years. 56.3% were male and 15.6% were diabetic. Mean follow up was 19.8 +/- 16.9 months. 18 patients were on continous ambulatory PD and 12 in automated PD. Mean serum ß2M levels before starting PD were 12.8 +/- 6.6 mg/l and they remained stable during follow up (12.9 +/- 5.2 mg/l, 15 +/- 4.2 mg/l, 14.3 +/- 6.9 mg/l, 10.2+/- 4.5 mg/l at month 6, 12, 24 and 36, respectively; p NS). No differences in serum ß2M levels were observed between continous ambulatory PD and automated PD. Serum ß2M levels were inversely and significantly correlated with weekly KtV (r= -0.943; p 0.009) and residual renal function (r= -0.829; p 0.042). One cardiovascular event was recorded during follow up. Conclusion Serum ß2M levels remain stable during follow up in our cohort of incident PD patients and is significantly and inversely correlated with weekly KtV and residual renal function. Serum ß2M levels monitoring could be helpful in these patients and would yield important information in this population.